Expression Language Data Types

The Java programming language on which the Expression Language is based is a strongly typed language, which means that every variable and every expression has a type that is known at parse time.

Types:

  • Limit the values that a variable can hold or that an expression can produce.

  • Limit the operations supported on those values.

  • Determine the meaning of the operations.

Strong typing helps detect errors at parse time.

The types of the Expression Language are divided into two basic categories:

  • Primitive types: The Boolean type and the numeric types. The numeric types are the integral types:

    • byte

    • short

    • int

    • long

    • BigInteger

    • char

    • floating-point types: float, double, and BigDecimal

  • Reference types:

    • class types

    • interface types

    • array types

    • a special null type.

      An object is a dynamically created instance of a class type or a dynamically created array. The values of a reference type are references to objects. All objects, including arrays, support the methods of class Object. String literals are represented by String objects.

The Cisco Unified CCX Expression Language also includes the friendly data type. A friendly data type is the Cisco Unified CCX data type that is the equivalent of a fully qualified Java class name, that is the Java data name and the package in which it is included. Friendly data types are either primitive or reference types. For more information on friendly data types, see Friendly Data Types.

Names of types or friendly type names are used in declarations, casts, array creation expressions, class literals, and instanceof operator expressions.

This section includes the following topics: